Motion-pictures projection device

ABSTRACT

Simplification of handling operations necessary for motionpicture projection and especially that of sound films. The film with its reels is carried in a magazine positioned flat-wise on the projector. This positioning operation engages the film in the clawed channel and in the sound-track reproduction device. A constant length of loop between the projection gate and the sound-head is ensured by regulating the film&#39;&#39;s unwinding motion obtained by means of a follower controlling the level of the belt interconnecting a set of opposite truncated pulleys inset in the transmission of the rotating motion to a friction type supplyroller of film.

United States Patent 1 1 3,694,060 Tadi i 1 1 Sept. 26, 1972 [54] MOTION-PICTURES PROJECTION 1,944,030 1/ 1934 Foster et al ..352/72 DEVICE 3,176,310 3/1965 Finnerty ..352/72 3 227 508 1/1966 Bavaro ..352/27 I t A F [72] :31; 32:1 22 g 3,479,114 l1/1969 Helnonen ..352/225 Filed? March 1970 Primary Examiner-S. Clement Swisher [21] APPL No; 24,050 Attorney-Johnson, Dienner, Emrich, Verbeck &

Wagner [30] Foreign Application Priority Data 57 ABSTRACT March 27, 1969 France ..6909121 Si lifi ti f handling operations necessary f motion-picture projection and especially that of sound [52] US. Cl. ...352/l4, 352/72, 352/225 fi|ms The m i its reels i carried i a magazine [51] hit. Cl. ..G03b 31/02, G031) H48. positioned fl i on h projector i positioning [58] Fleld Search""352/l4' operation engages the film in the clawed channel and 242/192 in the sound-track reproduction device. A constant length of loop between the projection gate and the [56] keterences C'ted sound-head is ensured by regulating the film s unwind- UNITED STATESPATENTS ing motion obtained by means of a follower controlling the level of the belt interconnecting a set of 3,404,938 10/1968 Kubmck ..352/104 opposite truncated pulleys inset in the transmission of gicKee the rotating motion to a friction type supply-roller of ennesseye a. film 3,008,661 11/1961 Estes et a1 ..352/77 1,001,098 8/ 191 l Vebelmesser ..242/ 192 10 Claims, 7 Drawing Figures PATENTEDsP2s I972 SHEET 1 BF 6 INVENTOR ANDRE FRANCIS TADIE fi w M v W ATTORNEYS PATENTEnsfiPzs I97? 3 694,060

SHEET 2 BF 6 FIG. 2

INVENTOR ANDRE FRANCIS TADIE PATENTEDsms 912 I 3,694,060

saw u 0F 6 FIG. 4

INVENTOR ANDRE FRANCIS TADIE BY 144/; 3 5M @Mf ATTORNEYS msmensevz m 3.694060 SHEET 5 OF 6 O In FIG. 5

INVENTOR ANDRE FRANCIS TADIE ATTORNEYS PATENTED SEP 2 6 I972 SHEET 6 0F 6 W ATTORNEYS I INVENTORS ANDRE FRANCIS TAD MOTION-PICTURES PROJECTION DEVICE The present invention concerns a motion-picture projection apparatus, that is to say, the projector itself together with the gear sewing to support and drive the film to be shown and to reproduce the sound-track going with this film.

It is a well-known fact that good synchronization of film-frames with the sound reproduced from the soundtrack of this same film demands constant and clearly defined adjustment of interval between the projection gate and the sound-head placed below this gate. For socalled super 8 films, this interval usually amounts to 18 frames, i.e. 85 mm in magnetic reproduction operation, and 22 frames in optical reproduction operation.

Between the two, seeing that the film cannot be kept tense because it runs intermittently opposite the projection gate, the length of the loop it forms must be kept at a constant average figure.

In normal projector installations, this result is obtained by setting, (below the sound-head at any rate, and preferably on either side of the projector-section including the projection gate and the sound-head), cogged film-feed pulleys which are synchronized so as to keep the length of film separating them constant.

This explains why the task of putting a sound-film in place in a normal projection unit is a lengthy and delicate operation compelling the operator to make the end part of the film follow a complex path between the feed-reel and the take-up reel.

The only known improvement of this technique consists in rendering part of this operation automatic by means of drive-pulleys and guides so that once the endpart of the film has been inserted by hand in the projectors inlet channel, this film automatically advances up to an exit channel located close to the take-up reel.

There also are projection apparatus designed to hold magazines containing films arranged in closed loop form. A loop of film escapes tangentially from the boss of a reel fitted with a single cheek, on the side without cheek, and is taken up on the circumferential part of the reel, so that thetraction ensuring film take-off, in making the reel turn, also ensures take-up of this film on the same reel.

The projectors equipped with such film magazines are not very good for sound-reproduction and can only serve for a specific type of magazine containing a looped film.

The present invention concerns a projection device applicable both for looped films stored in magazines and for ordinary films, eventually also set up on a detachable device acting as film magazine.

lt furthermore permits extremely simplified loading operations: once the film reel-or reels-magazine is set up on the device, loading can be reduced to manipulation of just one knob.

Thanks to this invention, it is possible to backtrack the film during its showing, to interrupt projection of one particular film at a given moment, replace it with another one, project this other film in part or in full, and finally resume showing of the first film at the point where it was interrupted.

This is a particularly valuable advantage for educational films; for example, when one given film can be made clearer by another, more elementary or more detailed one, the teacher immediately can switch to this second film.

With this device, it also is possible to use a wide variety of reel-sizes.

Lastly, and if necessary, the device permits film-rewinding on the supply reel, without it being required first to disengage the film.

The film projection device in terms of this invention incorporates (in a projector) a light source, a shutter, a projection gate comprising a a clawed channel which embodies a stationary apertured member having a channel or film guide and associated claw for intermittingly driving the film through said channel or guide in timed sequence to the shutter, a lens and a film driven-reel drive-mechanism. Said film guiding channel member is set horizontally in a vertical plane projecting from the top part of the projector, while a device capable of making the projected frame pivot around its center is set on the lighted projection path. The drivenreel is mounted on a pivot carried by a deck fitted with the means to position (on the top-side part of the projector) center and guide a film-loop so that it enters the film guide of the clawed channel member open, said positioning resulting in good cooperation between the driven-reel and the drive-mechanism.

The driven-reel drive-mechanism preferably consists of a power-roller flexibly pressed against a component concentric with the reel and solid with it.

In this way, it is not necessary to have great precision in order to put the deck in place on the apparatus since it will be enough that the film guiding-devices convey it to the film guiding channel member and associated film drive claw, which can be wide open, and that the roller solid with the reel be brought inside the action-zone of the drive-roller.

As will be seen further in the text, the above-mentioned roller solid with the driven-reel can consist of one side of the reel, or of a pulley carried by the reelpivot and accessible on the side of the deck opposite the one carrying the reel.

With looped films, the take-up reel intermingles with the unwinder. For a normal film, if two reels, the first one serving as supplier-reel, and the other driven, are used, these two reels can be superimposed and coaxial.

Lastly, and this is well-known, these two reels can be set up on the deck with their axes parallel.

In all cases, the decks equipped in this way constitute detachable film-holder magazines or loaders.

Regarding another aspect of this invention, over one section of the films path between the place where it is taken up and the point where it is unwound, and preferably close to the driven-reel, the film is nipped flat between a pressure-roller and a friction type supply-roller working at a more or less constant speed corresponding to the average film unwinding speed.

When the film incorporates a sound-track, the sound-head is set right next to the friction supply-roller, ahead or behind, and the speed of said supply-roller is controlled by a regulator, preferably incorporating a follower in contact with the loop the film forms between the clawed channel and the sound-head so as to keep the length of this loop constant.

The servo-system will preferably be mechanical and the follower adapted to the film combines, for example, with a progressive brake of the supply-roller driver, whose speed is selected too high. The follower can in this way control a fork acting on a belt running over two tapered pulleys in an inversed arrangement mounted on two parallel pins, one of which is driven by the same motor as the claws, and the other transmits its movement to said supply-roller. This roller can be solid with a fly-wheel serving to reduce excessively quick speed fluctuations and thereby avoid having flutters when reproducing sound.

To put the projector in service, the motor of the latter being permanently coupled with the supply-roller and with the driving-roller of the driven-reel, ,after starting-up this motor and lighting the lamp, a single control can ensure coupling of the motor with the clawmechanism, closing of the clawed channel over the inserted film, application of the film against the soundhead and its nipping between the supply-roller and the associated pressure-roller.

Further in this text, you will find among other things a detailed description of a projection apparatus intended for so-called super 8 films, incorporating, close to their single lateral line of punches, a magnetic, or optical reproduction sound-track. These films are convenient for small-size apparatus, both those used for shooting and for projection. Another description further on concerns a portable projection apparatus.

As will be seen, however, the present invention applies to all sorts of films, and especially to talking films.

The appended drawings show a number of nonrestrictive examples of makes based on the invention.

. In the drawings:

FIG. 1 is a plan view of the projector-part of the device in accordance with the relevant invention; the top plate of the projector having been removed to show the interior arrangement;

FIG. 2 is a section along II-ll of FIG. 1;

FIG. 3 is a schematic view of the chief components forming the device in accordance with this invention;

FIGS. 4, 5 and 6 are schematic views of film-rack decks usable with the projector shown in the preceding figures; and

FIG. 7 is a section along VII-VII of FIG. 6.

The projector shown in FIGS. 1 and 2 is mounted inside a box-shaped frame 1 which can be fitted, for transportation, with a handle 2 secured to one side of this frame by springs 3 when not in service. The detachable cover closing off this box is not shown.

The film s motion during projection is ensured from shaft 5 of electric motor 4. One of the ends of this shaft is solid with a pulley 6 which drives vertical-set pulley 8 via belt 7. Pulley 8 is solid with truncated pulley 9 (FIG. 3) whose largest end faces downwards. Through belt 10, truncated pulley 9 drives another truncated, vertical-set pulley l 1 whose largest end faces upwards.

v The base of this pulley 11 is solid with cylindrical I roller 12. Wheel 18 is mounted on a shaft 19 rotating inside frame 1 parallel with the axis of pulley 11. Between roller 12 and wheel 18, held fast by spring 13, is intermediate roller 14 which is mounted at the end of an articulated arm in two parts, 15, 16; part 16 is carried by pin 17 fixed to frame 1. Roller 12 can in this way transmit its rotating motion to wheel 18. Top end 19a of shaft 19 is used, as will be seen further in the text, as supply-roller for regulation of film A unwinding motion.

A sliding-gear comprising a pulley 20 can slide and turn on shaft 5 as well as semi-claw-clutch 21 working together with another half-clutch solid with shaft 5.

This portion of shaft 5 also is solid with ventilator 23 serving to cool off the projection lamp.

The two claw-clutch sections 21 and 22 are guided to engaged position by spring 24 inserted on shaft 5 and acting on the sliding-gear. However, the sliding-gear can be released by fork 26 inserted in its groove, the ends of which pivot in bearings 87 and 87a. This fork is solid with lever 86 whose role will be explained further in the text.

A belt 27 runs over pulley 20 of the slidinggear. This belt drives shaft 29 by means of pulley 28 (see also FIG. 3). Shaft 29 is solid with rotating shutter 30 (represented in FIG. 3 in the form of three separate blades fixed to a hub to make the function clearer) and earns 36 and 37 actuating the driving mechanism of claws 31 ensuring intermittent progression of film A in the projection gate 32.

Claws 31 are carried at the upper end of a lever 33 pivoting around a stationary axis 34 and designed with an opening 35 shaped like a parallel-edged frame. Triangular cam 36 turns inside this opening. This arrangement ensures back-and-forth motion of claws 31 more or less parallel to the lengthwise direction of film A. The perpendicular-direction motion of claws 31, serving to engage them in the perforations of film A and to release them from same, is obtained via cam 37 which displaces the upper part of lever 33 parallel to the axis of shaft 29 by flexible deformation process.

Film A is inserted in a channel constituted by a stationary part or apertured plate 38 solid with frame 1 and a film gate or pressure plate 39 supported and guided by nose-piece 41. The pressure needed to maintain the film in the channel comes from springs 40 which bear down on this nose-piece.

Nose-piece 41 is mounted on a lever 42 pulled by spring 43 to position 42a tilted forward so as to secure release from the clawed channel. Conversely, lever 42 can be pushed back and held up by cam 44 acting on teat 42b of lever 42', this cam is solid with shaft 45 maneuvered by means of start and stop button 46.

The film gate and the stationary part of channel 38 are provided with opposite rectangular openings cutout so as to delimit projection aperture 32. Each frame of the film passing through Channel 38 as it aligns with aperture 32 is lit by a lamp 47 and its reflector condenser 48.

The stream of light flows through lens 49 contained in nose-piece 41 and strikes a mirror 50 parallel with the clawed channel 31, 38 but aslant 45 in relation to the optical axis of the lens. Mirror 50 reflects the axial ray 51' vertically downwards, as shown in 52, then the light strikes the second mirror 53 also aslant 45 and parallel with the optical axis of the lens; this mirror 53 straightens the central projection ray horizontally, as shown in 54.

Through the action of mirrors 50 and 53, the projection is performed at right angles with the direction in which the light rays are emitted by the projection lamp, but the image is turned about its center. In this way, the frames of film A for which the vertical is aimed in the lengthwise direction of the film and which run off in recumbent position in the clawed channel 31, 38, are straightened by the set of mirrors 50-53.

Shaft 5 is solid at the other end with a pulley 55 which, via belt 56, drives double, intermediate pulley 57. The second belt 58 passing over this double pulley is returned in a horizontal plane by rollers 59, 60 and 61 for drive of pulley 62. The pins of rollers 60, 61 and that of pulley 62 are carried by a flat lever 63 pivoting about another pin 64 solid with the frame. This lever is pulled towards the back of the projector by spring 65.

Pulley 62 is solid with a driving-roller 66 intended, in certain cases, as will be explained further in the text, for drive of the take-up film-reel. Through belt 67, pulley 62 also drives a wheel 68 with rubbered rim 69 which is intended, in other cases, also for drive of a film-reel.

The film sound-track is reproduced by a device 73. The film is pressed against this sound-head by a support 70 carried by a lever 71 actuated by a spring 72 (FIG. 3). Reproduction device 73 can be magnetic; it could also be photoelectric. Preferably, the device provided with a magnetic sound-head at 73, can be equipped, in addition, with an optical sound-head placed after supply roller 19a, thanks to the difference of interval between frame and sound depending on whether recording is optical or magnetic. In addition, immediately after roller 19a, the film runs off more regularly than before. A single optical or magnetic soundhead can of course also be provided after roller 19a.

The optical reproduction light source can be lamp 47, thanks to a small mirror 75 and, if need be, an opening provided in reflector 48 (arrow 74).

Film A is pressed against supply roller 19a by means of a roller 76, the pin of which is carried by an arm 77. This arm is secured (but adjustable) on a lever 78 which is solid with its pivot pin. A second, hook-shaped arm 80 also is secured to this pin. Arm 80 is set up in such a way that it comes into contact with the pin of pulley 62 in order to shift flat lever 63 in opposition to spring 65. Lever 78 also is fitted with a second hook 81 capable of shifting one'finger of arm 71 (pivoting about stationary pin 71a) to release the film from sound-head 73. Another hook can be provided for if the device is equipped with two sound-heads.

As a result, and from the shown position, displacement of lever 78 in the direction indicated by arrow 82 shifts flat lever 63 in the direction indicated by arrow 83, that is to say, it releases the film from the various pressure organs.

It is hence possible to provide enlarged intervals between these different organs, which, without taking special precautions, permit insertion of the film inasmuch as this film is put in with its base opposite said enlarged intervals.

As will be seen in FIG. 3, sound-head 73 and its support, supply-roller 19a and pressure-roller 76, driver 66 and driving-wheel 68-69 are in projecting position in relation to plate 84 which partially closes off frame 1 and fit through this plate in adequate openings. The

' projection lamp and its reflector as well as the clawed channel also protrude from this plate.

The movement in accordance with arrow 82, or the opposite direction movement, which serves to press the film in the reproduction device and the driving device, is obtained via rod 85 which is articulated on cam 44, the result being that this rod and this cam form a crankrod system driven by shaft 45. It will be recalled that this cam serves to set nose-piece 41 in active position, which results in closure of the clawed channel for drive of the film in this channel. Cam 44 furthermore acts through its circumferential part on the end-section of lever 86, and causes coupling fork 26 inserted in groove 25 to pivot, hence controlling the movements of claws 31.

Truncated pulleys 9 and 11 and belt 10 are designed (as will be explained further in the text) to keep constant the length of the loop A, of film included between the frame passing at a given moment in the projection gate 32 and the point of film A which, at the same moment, is engaged in sound-head -73.

In this connection, loop A is in two-way contact with a follower 88 carried by the end of a lever 89 articulated about pin 90. The follower 88 is in fact made up of two branches 88a and 88b between which loop A, passes branch 88a ends in a concave guide 130 while branch 88b features a convex face.

The end-part of lever 89 opposite the follower is connected via link-rod 91 to a bell-wire lever 92 whose second arm ends in a fork 93 fitting over and under belt 10. As can be seen, the choice of length of link-rod 91 permits adjustment of the original height of belt 10 on the truncated pulleys for a specific position of follower 88. As will be seen further in the text, it is hence possible to make factory-adjustments of the traveling speed of claws 31 and of the speed of the supply roller, 19a.

Lastly, shaft 45 of handling knob 46 incorporates a cam 94 acting on a switch 95 for power-supply of lamp 47 and of sound-head 73. Transformer 96 furnishes the different voltages necessary for operation of the motor, for lighting the lamp and for power supply of this sound-reproduction device.

The projector shown in FIGS. 1 to 3 is designed for use with the racks shown in three different examples of makes in FIGS. 4 to 6.

These racks feature as common characteristics a deck 97 carrying the film-reels and a film-loop running through the projector. This deck fits into plate 84 to form the top-side of said projector. In this connection, each deck 97 features an opening 98 fitting about hood 99 (shown in cross-section view in FIG. 2) of the projection lamp and two lugs 100 which fit into openings (not shown) provided in plate 84 to center the deck correctly.

Opening 98 is bordered by a wall 101 while the deck is bordered by a wall 102, the combination of the two hence providing a U-channel for centering and guidance of the loop of film A passing through the projector. This guide-system, which can be cast in one piece with deck 97, can be replaced by detachable guides, rollers, stiff wires, etc. fixed to deck 97.

On the front side, in walls 101 and 102, we have gates 103 and 131 which release the film so that it can be inserted in the clawed channel and in follower 88; wall 102 and deck 97 are also in-cut on the side, as shown in 104 and 105, so as respectively to be fitted with the sound-reproduction device 70-73 and the supply and presser-rollers (19a and 76 respectively).

In the example illustrated by FIG. 4, film A is a closed loop, the major part of which, wound round itself, is carried by a reel 106 which rotates freely on pivot 107 and features a single cheek on the side of deck 97. This reel is designed to be driven by roller 66 pressing its rim by passing through hole 114 of deck 97. This action serves to complete and help the film drive operation obtained by means of claws 31 and rollers 19a and 76.

In this example, peripheral wall" 102 also encloses the reel and a cover (not shown) is planned so as completely to enclose the film mounted on the reel and the exterior loop of this film.

In FIG. 4, the portion of film A escaping (as per arrow 109) from the reel at the level of its hub, is guided between the two V-branches 110 and 111 respectively of a suitably bent metallic wire, the ends of which are fixed in peripheral wall 102. Branch 110 serves to determine the point where the film escapes from hub 112 of the reel, while branch 11] maintains (instead of the non-existent cheek) the reel-turns to 'stop the film from escaping from the reel. Lastly, guides 113 help to secure improved reel take-up as shown by the dotted lines in FIG. 4.

In the example shown in FIG. 5, two reels are mounted idle on the same axle 115 secured to deck 97. Upper reel 116 is the supply reel from which the film escapes while bottom reel 117 is a driven-reel passing through opening 1 17 with the help of roller 66, as in the previous example.

An arm 118 controlled by a spring inside its pivot bearing, regulates the film-output on the outlet side of the supply reel to make up for the jerks due to discontinuous traction of the film by claws 31. Arm 118 is extended beyond the pivot by an arm 119 whichwhen the deck is in place, is located close to a pin set at the end of a conductor-arm 133.

Arm 133 controls (by means of a switch) infeed of power-supply current to the projector. In the shown example, arm 133, which pivots about axis 135 in opposition to spring 139, is conductor and cooperates with a conductor blade 136, the circuit being closed by con- 7 duo-tors 134 and 138.

In this way, when the tension of the portion of film exiting from supply reel 116 becomes too great, arm I19 shifts arm 133 about pin 135 away from blade 136 and the projector stops completely since it no longer is power-supplied: this prevents destruction of the films perforations by the claws. Something of the sort can happen accidentally, however, when the supply-reel has trouble in performing its function (defective reel, reel-cheeks crushed, etc.), or else normally, at the end of the film, when its end-piece is caught in the hub of the supply-reel and hence stopped. The projector thus stops automatically when the film showing comes to an end. Arm 133 is now released and the power supply circuit is re-established through the action of spring 139.

The example shown in FIG. 5 can also be designed, like the one shown in FIG. 4, in magazine form. That is to say, wall 102 can also enclose both reels 116 and 117 and a cover can be provided to enclose the lot. However, in that case, after a given showing, the film must be rewound on reel 116 outside of the projector by means of a device not shown here.

In the example shown in FIG. 6, the supply-reel 116 and reel 117 are solid in rotation with their shafts 120 which, as shown in FIG. 7, are solid underneath deck 97, with disks 121. Disk 121 of reel 117 is designed to be pressed by rim 69 of wheel 68 when lever 62 is pulled by spring 65 (FIG. 3).

Disk 121 associated with reel 116 is provided to rewind the film. To this end (see FIGS. 2 and 3) bent lever 122, articulated on stationary axis 123 solid with frame 1 carries the two flexible-rim rollers 126 and 127 (combined by means of angle pinions 124 and 125).

If we press down on the end 122a of lever 122, roller 127 comes into contact with the end-part of shaft 5, is put in motion and as a result, roller 126 which, by virtue of this operation, comes into contact with disk 121 made solid with reel 116, can drive this reel in the opposite direction so as to re-wind the film. Contrarily to normal projection apparatus, this operation is performed with the film in place in the apparatus and simply released from the presser, the sound-head and supply-roller 19a. Rollers 128 as well as arm 118 serve as guide for unwinding or rewinding purposes. During a given projection, it is possible-by stopping and releasing the film, to rotate reel 116 backward by hand so as immediately to show again a film sequence which it is desired to stress, for example.

To put in service the above-described installation for a film-showing, knob 46 is originally in position Ar on FIG. 3. In this position, and through the action of cam 44, film gate 39 is pivoted away from apertured plate 38 so that the clawed channel is wide open owing to the forward-tilting of nose-piece 41 in position 42a (FIG. 2). Clutch 21, 22 is disengaged, and there are relatively important intervals respectively between supply-roller 19a and presser-roller 76, between sound-head 73 and its support 70.

By working a switch (not shown), the motor is first started up. Through pulley 6, truncated pulleys 9 and 1 l and intermediate roller 14, wheel 18 is launched and gradually reaches its service speed. Driving-roller 66 and wheel 68 also rotate.

Following this starting operation and before maneuvering knob 46, one of the racks shown in FIGS. 4 to 6 is placed on upper plate 84 of the projector. Because the loop of film exterior to the reels is guided in the U- channel formed by walls 101 and 102, the film automatically places itself between the stationary apertured plate 38 and pressure plate 39 of the clawed channel, in the fork of follower 88, between sound-head 73 and its support and between rollers 19a and 76.

It is then possible without further precautions to change knob 46 over from Ar position to Ma position, in the direction indicated by arrow 129. Through this movement, cam 44 pushes back lever 41 against 43, which fact closes the channel. At the same time, lever 86 fitted with clutch-fork 26 brings the two halfclutches 21 and 22 together and these are pressed against one another by spring 24. The tipping of lever 78 driven by rod squeezes the film in the reproduction device and in supply-roller 19a-76. Hook 80 releases lever 63 which, as it pivots about its axis 64, actuates the rotating motion of the driven or take-up reel. At the movement's limit point, switch causes lamp 47 to light and the sound-head is power-supplied.

In the examples illustrated by FIGS. 4 and 5, roller 66 is the active element while in the example of FIG. 6, it is wheel 68 which acts to drive shaft carrying reel 117.

As indicated earlier, the length of the connection-rod 91 has been adjusted beforehand so that the rotating speed of 19a roller correspond as accurately as possible to the average intermittent run-off speed of the frames in the projection gate.

However, if the film loop A between the projection gate and the reading-head 73 tends to become larger, it exerts a thrust-movement on concave guide 130 and causes follower 88 to tip to the right, so that fork 93 slightly depresses belt 10 on the truncated pulleys. Pulley 11 now increases its speed a little and by way of consequence, wheel 18 tends to accelerate. However,

the weight of. this wheel is enough for the variation to be relatively slow, i.e. there will be no important variation of the sound-frequency, a phenomenon known as flutter.

Conversely, if loop A of the film tends to diminish in length, it exerts pull on branch 88b of the follower, which causes wheel 18 to slow down because belt 10 now moves upwards on the truncated pulleys.

Instead of a forked-follower acting two-ways on the film, the follower can act only on the side of the film without sensitive layer (the side facing the lens in case of a film obtained by contact-printing). This eliminates the risk of scratching the film layer. Permanent contact of the follower with the film can be ensured by means of a spring; to put it more simply, this contact can be ensured by the sole weight of belt 10 which tends to drop of its own accord especially if the descending taper of reel- 11 is smaller than the ascending taper of reel In addition, to avoid the risk of having to adjust the focus each time the clawed channel is opened, the nose-piece can be supplied stationary and independent of this clawed channel, the latter opening in that case only when acting upon knob 46.

The present invention makes it possible to prepare in advance the films to be shown, and they can also be put in place very quickly and very easily. It furthermore makes it possible to stop the film'projection at will, to backtrack and even change films and possibly resume the first showing after that. This invention is therefore particularly convenient for the educational applications of film projections and for the audio-visual teaching methods. It also is convenient for showings of amateurs films owing to its great handling ease. It can also serve for films teaching how to prepare and mount professional films.

Having described my invention, I claim:

1. In a motion-picture sound projector, the combination of a light source, an objective spaced axially forwardly thereof, and an intermediately disposed axially aligned film gate therebetween which includes a stationary film aligning channel member and a resiliently backed apertured pressure plate, an intermittent film drive means associated with the channel member for effecting intermittent movement of a film past the film gate, a sound-head and rotatable film drive means for engaging and effecting continuous movement of said film past the sound head, said sound-head and rotatable film drive means being disposed with the film gate and the intermittent film drive means at a common level in the projector, said sound-head and rotatable film drive means each having an associated pressure member for engaging the side of film opposite its engagement by the sound-head and rotatable drive means, actuating means which simultaneously displace said apertured pressure plate and pressure members to an open position with respect to the film aligning channel member, sound head and rotatable film drive means to accommodate location of the cartridge film therebetween, and a film containing cartridge having an outer film guiding channel, said cartridge being insertable into the projector with its channel located at said level when the actuating means has displaced said apertured pressure plate and pressure members to their open positions, the walls of said channel of the film containing cartridge having a first cut out which receives the stationary channel member, associated intermittent film drive and apertured pressure plate of said film gate, and additional cutouts spaced therefrom to receive said sound-head, rotatable film drive means and their associated pressure members when the cartridge is properly positioned within the projector with its film guiding channel at said level, the walls of the film guiding channel member between said cut-outs serving to automatically locate the cartridge film in position between the respective film aligning channel members, sound-head, film drive means and associated apertured pressure plate and pressure members when in their said open positions, and said actuating means being thereafter operable to simultaneously close the apertured pressure plate and pressure members to engage the film opposite its engagement by the respective film aligning channel member, sound head and rotatable drive means to ready the projector for projection of the cartridge film.

2. The combination of claim 1 wherein the film containing cartridge includes a central opening about which the film guiding channel extends in a generally U-shape, said central opening serving to receive the light source when the cartridge is properly positioned in the projector.

3. The combination of claim I wherein the cartridge includes a driven-reel onto which the film is wound and the projector includes a displaceable tangent action roller which flexibly engages said driven wheel when the cartridge is properly positioned in the projector.

4. In a motion picture sound projector, the combination of a light source, an objective spaced axially forwardly thereof, and an intermediately disposed axially aligned film gate therebetween which includes a-stationary film aligning channel member and a resiliently backed apertured pressure plate, an intermittent film drive means associated with the channel member for effecting intermittent movement of a film past the film gate, a sound-head and an associated continuously rotating film drive means for effecting continuous movement of said film past the sound-head, said soundhead and associated film drive means being spaced from the film gate and the intermittent film drive means and disposed therewith at a common level in the projector, said sound-head and continuously rotating film drive means each having an associated pressure member by which the film may be positioned in operative relation therewith, actuating means operatively connected to said apertured pressure plate and pressure members to simultaneously displace the same to an open position with respect to the film aligning channel member, sound-head and film drive means to accommodate location and removal of the film from therebetween, and means operated by said actuating means which halt the intermittent drive means when the apertured pressure plate is displaced to its open position, and a film containing cartridge having an outer film guiding channel, said cartridge being insertable into the projector with its channel located at said level when the actuating means has displaced said apertured pressure plate and pressure members to their' open positions, the walls of said channel of the film containing cartridge having cut-outs which are spaced to receive said film gate, sound-head, intermittent and continuously rotating film drive means and associated pressure members when the cartridge is properly positioned within the projector with its film guiding channel at said level, the walls of the film guiding channel member between said cut-outs serving to automatically locate the cartridge film in position between the respective film aligning channel members, sound-head, film drive means and associated apertured pressure plate and pressure members when in their said open positions, and said actuating means being thereafter operable to simultaneously close the apertured pressure plate and pressure members to the respective film aligning channel member, sound-head and continuous drive means and restart the intermittent drive means to initiate film and sound projection once the cartridge has been properly located in the projector.

5. In a motion-picture sound projector, the combination of a light source, an objective spaced axially forwardly thereof and an intermediately disposed axially aligned film gate which includes a stationary film aligning channel member, an intermittent film drive means associated with said channel member and a displaceable apertured pressure plate for resiliently holding film in said channel member and positioned for driving engagement by the intermittent film drive means, a film containing cartridge having an outer film guiding channel which is located between the light source and objective when the cartridge is properly positioned in the projector, the cartridge including a driven reel onto which the film is wound and the projector including a displaceable tangent action roller which flexibly engages said driven wheel when the cartridge is properly positioned-in the projector, said film guiding channel of the cartridge havinga cut-out portion which receives the stationary channel member, associated intermittent film drive means and apertured pressure plate of the film gate, and means for displacing said apertured pressure plate from the stationary channel member of the film gate so as to facilitate the location of the film in said channel member of the film gate as the cartridge is positioned in the projector and its film guiding channel aligned between the light source and objective, the combination further including actuating means which simultaneously displace said roller with the apertured pressure plate to facilitate insertion and removal of the cartridge from the projector, said actuating means serving also to declutch the intermittent film drive means when said roller and apertured pressure plate are displaced.

6. In a motion-picture sound projector, the combination of a light source, an objective spaced axially forwardly thereof and an intermediately disposed axially aligned film gate which includes a stationary film aligning channel member, an intermittent film-drive means associated with said channel member and a displaceable apertured pressure plate for resiliently holding film in said channel member and positioned for driving engagement by the intermittent film-drive means, a film containing cartridge wherein the film is supported by the cartridge in closed-loop form and is carried by one reel with a single cheek, the strip of film escaping from the reel on the opposite side being guided between two V-branches of a rigid bent wire, one branch of which is applied against the contiguous spirals of film carried by the reel, said cartridge having an outer film guiding channel which is located between the light source and objective when the cartridge is properly positioned in the projector, said film guiding channel of the cartridge having a cut-out portion which receives the stationary channel member, associated intermittent film drive means and apertured pressure plate of the film gate, and means for displacing said apertured pressure plate from the stationary channel member of the film gate so as to facilitate the location of film in said channel member of the film gate as the cartridge is positioned in the projector and its film guiding channel aligned between the light source and objective.

7. In a motion-picture sound projector, a light source and an objective axially spaced forwardly thereof, a motor, a rotatable shutter operatively driven by said motor to intermittently interrupt the projection of light from said source by said objective, a film projection gate having an aperture in the path of the light from said source to the objective, and intermittent film drive means operatively connected to said shutter motor for sequentially locating and holding each frame of the film in alignment with the aperture of said film gate in timed sequence with the operation of the shutter, a sound head spaced from the apertured film gate, a rotatable capstan for continuously moving the film exiting from the film gate past the sound-head, the film exiting from the film-gate forming a slack loop therebetween and said sound'head, a follower sensing the size of said slack loop, a larger-diametered drive wheel mounted concentric with said capstan so that the capstan rotates therewith, a first truncated pulley having a cylindrical portion concentric therewith and in driving relation to said larger-diametered drive wheel to rotate the capstan, a second truncated pulley oppositely arranged to said first truncated pulley, said second truncated pulley being drivingly connected to the motor which operates said shutter and intermittent film-drive means so as to be continuously rotated therewith, a connection belt between said truncated pulleys by which the second truncated pulley rotates the first truncated pulley, means for changing the position of said connection belt axially of the two pulleys so as to vary the speed at which the second pulley rotates the first pulley, said means being responsive to movement of the follower as it senses a change in the size of the slack loop of film between the film gate and sound-head to thereby regulate the speed at which the continuous drive means moves the film past the sound-head and to maintain the film slack loop to a substantially constant size, and the diameter and weight of said drive wheel being so related to the capstan and the first truncated pulley as to dampen speed rotation variations of the capstan in response to sudden changes in speed of the first truncated pulley.

8. The combination of claim 7 wherein the axes of the truncated pulleys are vertically disposed, the follower being pivotally mounted about a horizontal axis and connected by associated linkage to said connecting belt such that'the weight of the belt forces the follower against one side of the film slack loop and the film slack loop acting on the follower in one direction of its change in size to resist said force exerted thereon by the weight of the belt.

9. The combination of claim 7 wherein the film gate includes a stationary channel member and a displaceable aperture pressure plate for resiliently holding film in the channel member and in position for driving engagement by the intermittent film-drive means, the film means being contained in a cartridge having an outer film guiding channel which is located between the light source and objective when the cartridge is properly positioned in the projector, said film guiding channel of the cartridge having a cut-out portion which receives the stationary aperture channel member, associated intermittent film drive means and apertured pressure plate of the film gate, actuating means which displace and hold said apertured pressure plate from the stationary channel member of the film gate in order to facilitate location of the film in said channel member of the film gate as the cartridge is positioned in the film guiding channel aligned between the light source and objective, said actuating means being operable to close the apertured pressure plate against the opposite side of the film once the cartridge is positioned in the projector.

10. The combination of claim 9 wherein said actuating means simultaneously declutch the intermittent film drive means and shutter from its driving motor when the apertured pressure plate is displaced. 

1. In a motion-picture sound projector, the combination of a light source, an objective spaced axially forwardly thereof, and an intermediately disposed axially aligned film gate therebetween which includes a stationary film aligning channel member and a resiliently backed apertured pressure plate, an intermittent film drive means associated with the channel member for effecting intermittent movement of a film past the film gate, a sound-head and rotatable film drive means for engaging and effecting continuous movement of said film past the sound-head, said soundhead and rotatable film drive means being disposed with the film gate and the intermittent film drive means at a common level in the projector, said sound-head and rotatable film drive means each having an associated pressure member for engaging the side of film opposite its engagement by the sound-head and rotatable drive means, actuating means which simultaneously displace said apertured pressure plate and pressure memberS to an open position with respect to the film aligning channel member, sound head and rotatable film drive means to accommodate location of the cartridge film therebetween, and a film containing cartridge having an outer film guiding channel, said cartridge being insertable into the projector with its channel located at said level when the actuating means has displaced said apertured pressure plate and pressure members to their open positions, the walls of said channel of the film containing cartridge having a first cut out which receives the stationary channel member, associated intermittent film drive and apertured pressure plate of said film gate, and additional cutouts spaced therefrom to receive said sound-head, rotatable film drive means and their associated pressure members when the cartridge is properly positioned within the projector with its film guiding channel at said level, the walls of the film guiding channel member between said cut-outs serving to automatically locate the cartridge film in position between the respective film aligning channel members, sound-head, film drive means and associated apertured pressure plate and pressure members when in their said open positions, and said actuating means being thereafter operable to simultaneously close the apertured pressure plate and pressure members to engage the film opposite its engagement by the respective film aligning channel member, sound head and rotatable drive means to ready the projector for projection of the cartridge film.
 2. The combination of claim 1 wherein the film containing cartridge includes a central opening about which the film guiding channel extends in a generally U-shape, said central opening serving to receive the light source when the cartridge is properly positioned in the projector.
 3. The combination of claim 1 wherein the cartridge includes a driven-reel onto which the film is wound and the projector includes a displaceable tangent action roller which flexibly engages said driven wheel when the cartridge is properly positioned in the projector.
 4. In a motion picture sound projector, the combination of a light source, an objective spaced axially forwardly thereof, and an intermediately disposed axially aligned film gate therebetween which includes a stationary film aligning channel member and a resiliently backed apertured pressure plate, an intermittent film drive means associated with the channel member for effecting intermittent movement of a film past the film gate, a sound-head and an associated continuously rotating film drive means for effecting continuous movement of said film past the sound-head, said sound-head and associated film drive means being spaced from the film gate and the intermittent film drive means and disposed therewith at a common level in the projector, said sound-head and continuously rotating film drive means each having an associated pressure member by which the film may be positioned in operative relation therewith, actuating means operatively connected to said apertured pressure plate and pressure members to simultaneously displace the same to an open position with respect to the film aligning channel member, sound-head and film drive means to accommodate location and removal of the film from therebetween, and means operated by said actuating means which halt the intermittent drive means when the apertured pressure plate is displaced to its open position, and a film containing cartridge having an outer film guiding channel, said cartridge being insertable into the projector with its channel located at said level when the actuating means has displaced said apertured pressure plate and pressure members to their open positions, the walls of said channel of the film containing cartridge having cut-outs which are spaced to receive said film gate, sound-head, intermittent and continuously rotating film drive means and associated pressure members when the cartridge is properly positioned within the projector with its film guiding channel at said level, the walls of thE film guiding channel member between said cut-outs serving to automatically locate the cartridge film in position between the respective film aligning channel members, sound-head, film drive means and associated apertured pressure plate and pressure members when in their said open positions, and said actuating means being thereafter operable to simultaneously close the apertured pressure plate and pressure members to the respective film aligning channel member, sound-head and continuous drive means and restart the intermittent drive means to initiate film and sound projection once the cartridge has been properly located in the projector.
 5. In a motion-picture sound projector, the combination of a light source, an objective spaced axially forwardly thereof and an intermediately disposed axially aligned film gate which includes a stationary film aligning channel member, an intermittent film drive means associated with said channel member and a displaceable apertured pressure plate for resiliently holding film in said channel member and positioned for driving engagement by the intermittent film drive means, a film containing cartridge having an outer film guiding channel which is located between the light source and objective when the cartridge is properly positioned in the projector, the cartridge including a driven reel onto which the film is wound and the projector including a displaceable tangent action roller which flexibly engages said driven wheel when the cartridge is properly positioned in the projector, said film guiding channel of the cartridge having a cut-out portion which receives the stationary channel member, associated intermittent film drive means and apertured pressure plate of the film gate, and means for displacing said apertured pressure plate from the stationary channel member of the film gate so as to facilitate the location of the film in said channel member of the film gate as the cartridge is positioned in the projector and its film guiding channel aligned between the light source and objective, the combination further including actuating means which simultaneously displace said roller with the apertured pressure plate to facilitate insertion and removal of the cartridge from the projector, said actuating means serving also to declutch the intermittent film drive means when said roller and apertured pressure plate are displaced.
 6. In a motion-picture sound projector, the combination of a light source, an objective spaced axially forwardly thereof and an intermediately disposed axially aligned film gate which includes a stationary film aligning channel member, an intermittent film-drive means associated with said channel member and a displaceable apertured pressure plate for resiliently holding film in said channel member and positioned for driving engagement by the intermittent film-drive means, a film containing cartridge wherein the film is supported by the cartridge in closed-loop form and is carried by one reel with a single cheek, the strip of film escaping from the reel on the opposite side being guided between two V-branches of a rigid bent wire, one branch of which is applied against the contiguous spirals of film carried by the reel, said cartridge having an outer film guiding channel which is located between the light source and objective when the cartridge is properly positioned in the projector, said film guiding channel of the cartridge having a cut-out portion which receives the stationary channel member, associated intermittent film drive means and apertured pressure plate of the film gate, and means for displacing said apertured pressure plate from the stationary channel member of the film gate so as to facilitate the location of film in said channel member of the film gate as the cartridge is positioned in the projector and its film guiding channel aligned between the light source and objective.
 7. In a motion-picture sound projector, a light source and an objective axially spaced forwardly thereof, a motor, a rotatable shutter operatively dRiven by said motor to intermittently interrupt the projection of light from said source by said objective, a film projection gate having an aperture in the path of the light from said source to the objective, and intermittent film drive means operatively connected to said shutter motor for sequentially locating and holding each frame of the film in alignment with the aperture of said film gate in timed sequence with the operation of the shutter, a sound head spaced from the apertured film gate, a rotatable capstan for continuously moving the film exiting from the film gate past the sound-head, the film exiting from the film-gate forming a slack loop therebetween and said sound-head, a follower sensing the size of said slack loop, a larger-diametered drive wheel mounted concentric with said capstan so that the capstan rotates therewith, a first truncated pulley having a cylindrical portion concentric therewith and in driving relation to said larger-diametered drive wheel to rotate the capstan, a second truncated pulley oppositely arranged to said first truncated pulley, said second truncated pulley being drivingly connected to the motor which operates said shutter and intermittent film-drive means so as to be continuously rotated therewith, a connection belt between said truncated pulleys by which the second truncated pulley rotates the first truncated pulley, means for changing the position of said connection belt axially of the two pulleys so as to vary the speed at which the second pulley rotates the first pulley, said means being responsive to movement of the follower as it senses a change in the size of the slack loop of film between the film gate and sound-head to thereby regulate the speed at which the continuous drive means moves the film past the sound-head and to maintain the film slack loop to a substantially constant size, and the diameter and weight of said drive wheel being so related to the capstan and the first truncated pulley as to dampen speed rotation variations of the capstan in response to sudden changes in speed of the first truncated pulley.
 8. The combination of claim 7 wherein the axes of the truncated pulleys are vertically disposed, the follower being pivotally mounted about a horizontal axis and connected by associated linkage to said connecting belt such that the weight of the belt forces the follower against one side of the film slack loop and the film slack loop acting on the follower in one direction of its change in size to resist said force exerted thereon by the weight of the belt.
 9. The combination of claim 7 wherein the film gate includes a stationary channel member and a displaceable aperture pressure plate for resiliently holding film in the channel member and in position for driving engagement by the intermittent film-drive means, the film means being contained in a cartridge having an outer film guiding channel which is located between the light source and objective when the cartridge is properly positioned in the projector, said film guiding channel of the cartridge having a cut-out portion which receives the stationary aperture channel member, associated intermittent film drive means and apertured pressure plate of the film gate, actuating means which displace and hold said apertured pressure plate from the stationary channel member of the film gate in order to facilitate location of the film in said channel member of the film gate as the cartridge is positioned in the film guiding channel aligned between the light source and objective, said actuating means being operable to close the apertured pressure plate against the opposite side of the film once the cartridge is positioned in the projector.
 10. The combination of claim 9 wherein said actuating means simultaneously declutch the intermittent film drive means and shutter from its driving motor when the apertured pressure plate is displaced. 